Reversible ribbon feed mechanism



Feb. 2, 1937. G. M. SACERDOTE REVERSIBLE RIBBON FEED MECHANISM Filed July 6, 1934. 4 Sheets-Sheet l INVENTOR Feb. 2, 1937. G. M. SACERDOTE REVERSIBLE RIBBON FEED MECHANISM 4 Sheets-Sheet 2 Filed July 6, 1934 INVENTOR Feb. 2, 1937. G. M. SACERDOTE 7 REVERSIBLE RIBBON FEED MECHANISM Filed July 6, 1954 4 Sheets-Sheet s INVENTOR www rem, Z, 1937. s. M. SACERDOTE,

REVERSIBLE RIBBON FEED MECHANISM Filed July 6, 1934 4 sheets sheet 4 INVENTOR Patented F eb. 2, 1937 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to devices, such as typewriters, adding machines, and the like, where a printing ribbon is employed, and more particularly refers to improvements in ribbon feeding and feed reversing mechanisms.

The invention is equally as well applicable in connection with the printing ribbon forming part of the standard equipment of devices of the character mentioned and with an auxiliary ribbon, or ribbons, such as may be employed in manifolding typewriters and like machines, for the purpose of making copies; although the invention is more especially intended for use in connection with devices of the latter type, where the ribbon runs along the. entire length of the platen and must at all times be maintained taut along the printing line.

The primary object of this invention accordingly is to provide a ribbon feed mechanism of a novel and improved design, whereby the ribbon is caused to be alternately wound upon one reel and unwound from another, and where suitable arrangements are made insuring at all times a taut condition of said ribbon.

Another object is to provide in a device of the character specified a ribbon feed mechanism combining with a minimum number of parts a maximum of reliability and simplicity of operation.

A further object is to provide, in a. ribbon feed mechanism, including two ribbon reels, novel and improved means for causing the reversal of the ribbon feed.

A still further object is to provide, in a device of the character specified, a novel and improved mechanism for reversing the ribbon feed, said mechanism being directly controlled by the ribbon itself and being preferably adapted to reverse the ribbon feed by a snap action.

Other objects and advantages of the present invention will more fully apear as the description proceeds and will be set forth and claimed in the appended claims.

The invention is illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a fragmentary front vertical section through the top of the frame of a typewriting machine, equipped with a manifolding attach ment embodying my invention;

Fig. 2 is a plan view of the same;

Fig. 3 is a rear view in elevation of the upper part of the typewriter, with the manifolding attachment mounted on the carriage thereof, shown in Figs. 1 and 2;

Fig. 4 is a side view in elevation of the typewriter, together with the manifolding attachment;

Fig. 5 is a detail vertical longitudinal section, in enlarged scale, illustrating the reversible ribbon feed mechanism, embodying my invention;

Fig. 6 is a detail view illustrating the disconnected position of one of the clutches, shown in Figs. 2, 3, and 5;

Fig. '7 is a similar view illustrating the connected position of said clutch;

Fig. 8 is a detail illustrating the manner of actuating the ribbon feed reversing mechanism;

Fig. 9 is a cross section through the arm actuating the ribbon feed reversing mechanism;

Fig. 10 is a fragmentary vertical section of the unidirectional driving mechanism controlling the ribbon feed;

Fig. 11 is a horizontal section through line ll-ll of Fig. 10; and

Fig. 12 is a horizontal section of the same through line l2--l2 of Fig. 10.

The drawings illustrate the invention as applied in connection with a manifolding or copying attachment mounted on the carriage of an Underwood typewriter. In the same 20 designates the typewriter frame, on which is mounted a traveling carriage 2|, carrying the platen 22. On said carriage is mounted the manifolding attachment frame 23, secured onto the carriage at each end thereof by means of screws 24. Said attachment frame is formed with two side uprights 25, 26, and a shaft 21 runs across said uprights and carries at each end one of the auxiliary ribbon reels 28, 29. Said reels are mounted loosely on said shaft, one or the other being operatively connected thereto by means of the reversible clutch mechanism which will be described later.

As clearly shown in Figs. 1, 2 and 4, the auxiliary ribbon 30 runs from one of the reels, 29, over an idler roller 3| at the front, then downwardly to the guide member 32, having a 45 deflecting slot 33, then horizontally along the platen in correspondence with the writing line to another deflecting slot 34, provided in a guide member 35 at the other end, then upwardly to another guiding roller 36 and reel 28. It is thus seen that by virtue of this arrangement the take-up reel will pull the auxiliary ribbon along the writing line each time the ribbon feed is operative, the other reel paying the ribbon in accordance with the angular movement of the take-up reel.

In the arrangement shown, shaft 21 is rotated a certain quantity in one direction to advance the auxiliary ribbon during the return movement of the carriage and its movement of rotation is transmitted to the take-up reel by means of a suitable clutch mechanism.

The clutch mechanism comprises a clutch member 31, fixed on shaft 21, for reel 28. Said clutch mechanism also comprises a clutch member 39, shiftable in and out of mesh with clutch member 31 and a clutch member 40, shiftable in and out of mesh with clutch member 38, said shiftable clutch members being slidably keyed on sleeves 4|, 42, respectively, which are loose on shaft 21.

Said sleeves 4|, 42 extend through uprights 25, 26, respectively, and have their outer end formed integral with or carrying fixed thereto a friction disk, such as 43, 43', the ribbon reel being loosely mounted on the shaft, but being engaged by a pin 44, carried by the sleeve, and being secured in position by a nut 44'.

The inner portion of each sleeve 4|, 42, is provided with adjusting nuts, such as 45, against which bears a spring 46, tending to force the sleeve inwardly, so that due to the action of said spring the friction disk carried at the outer end of the sleeve will bear against the friction disk 41, fixed on the corresponding upright.

Clutch members 39, 40, are controlled by shifting levers 48, 49, respectively, fixed on a shifting rod 50, said levers 48, 49 being positioned so that when one of the shiftable clutch members is in driving engagement with its respective fixed clutch member, the other shiftable clutch member is disengaged from its corresponding fixed clutch member. Thus in Fig. 5, it is seen that shiftable clutch member 39 is engaged with fixed clutch member 31 and shiftable clutch member 40 is disengaged from its corresponding fixed clutch member 38, so that in this position reel 28 is the take-up reel and reel 29 is the paying reel. If rod 50 is shifted to the left the conditions will be reversed and shiftable clutch member 40 will become operative while shiftable clutch member 39 will become inoperative.

The operation of shifting rod 50 is controlled by the ribbon itself, which when entirely unwound from the paying reel will exert a pull on a crank lever, causing an angular displacement thereof, the movement of said crank lever being transmitted to the shifting rod.

Thus when the ribbon is entirely unwound from paying reel 29, a pull will be exerted on arm 5| of crank lever 52, (see Fig. 2) pivoted at 53, so as to produce an inward movement of short arm 54 of said crank lever. When reel 28 is the paying reel and the ribbon is entirely unwound therefrom, a. pull will be exerted on arm 55 of crank lever 56, pivoted at 51, so as to cause the short arm 58 of said crank lever to move inwardly. Arm 54 of crank lever 52 is connected to shifting rod 50 by means of a tension spring 59, and arm 58 of crank lever 56 is connected to shifting rod 50 by means of a tension spring 60. The shifting movement of rod 50 from each of its extreme positions to the other is opposed by a spring 6 I, bearing against one or the other face of a double conical friction shoe 62 fixed on rod 50.

It will be seen that by virtue of this arrangement, when the ribbon has been entirely unwound from the paying reel and a pull is exerted thereby upon the long arm of its corresponding crank lever, before the short arm of said crank lever can actually cause the shifting movement of rod 50, it must extend its corresponding spring 59 or 60, so as to accumulate sufficient energy to overcome the resistance offered by spring 6| bearing against the friction shoe 62.

When suflicient energy has thus been stored in spring 59 or 60, the shifting movement of rod 50 will take place with a snap action, so that the reversal of the ribbon feed is effected instantly without lag and without giving the ribbon a chance to become slack.

Crank levers 52, 56 are actuated by the ribbon through the intermediary of two pull links, such as shown at 63, in Figs. 4, 8, 9, connected one to the end of arm 5| of crank lever 52 and the other, 64, to the arm 55 of crank lever 56. Referring more particularly to Figs. 2, 4 and 8, it is seen that link 63 is connected to the outer end of arm 5|, as shown at 65, and extends frontwardly thereof directly under reel 29. At this front end said link is formed with a slot 66, through which ribbon 30 is inserted. At a point in proximity of each one of its ends said ribbon is provided with a projecting lug or eyelet, such as shown at 61, which when the ribbon is about to be entirely unwound will bear against the slotted portion 68 of the link and will cause said link to follow the translatory movement of the ribbon. The link will, therefore, exert a pull upon its corresponding crank lever, which will actuate the shifting rod 50 in the manner hereinbefore explained.

The ribbon feed mechanism just described is shown actuated by a driving mechanism, such as illustrated and described in another patent application entitled Ribbon advancing mechanism, Serial No. 734,016, copending herewith.

Such an arrangement does not entail the necessity of performing any machining operation upon or of making any material additions to the structure of the typewriter itself. To this end, the return movement of the carriage is transmitted to the ribbon feed mechanism by means of a flexible element 69, wound upon a drum 10, and having its outer end anchored to the typewriter frame, as shown at 1| in Fig. 3.

When the carriage is moved back, that is, to the right with respect to Fig. 2 and to the left with respect to Fig. 3, the pull exerted by flexible element 69 upon drum 18 will cause said drum to rotate and to actuate a pinion 12, meshing with a gear wheel 13, mounted on shaft 21. When the carriage advances step by step as a line is being written, the drum will automatically take up the flexible element by the action of a spring. The construction of the drum and associated parts is shown in Figs. 10, 11, 12. In the same and in Fig. 3 it is seen that the drum 10 is rotatably mounted on a vertical shaft 14, in proximity of the lower end thereof, said shaft being rotatably mounted on vertical support 15 and having its lower end rotatably supported by a bearing 16, forming part of a supporting plate 11, upon which the drum rests.

The drum is connected to bearing 16 by a spiral spring 18, the tension of which will be increased when the drum is rotated by the pull exerted upon it by flexible element 69 during the return movement of the carriage. During these rotations the drum will cause vertical shaft 14 to also rotate, said drum carrying a pawl 19, engaging a ratchet wheel 80, mounted at the lower end of shaft 14. Thus, the return movement of the carriage will ultimately be transmitted to shaft 21 in the ribbon advancing direction. When the carriage is advanced step by step in the opposite direction, spring 18 will cause drum 10 to take up the flexible element and during this return movement of the drum pawl 19 will merely ride over the teeth of ratchet wheel without imparting any movement thereto.

It is readily seen that the driving mechanism shown and described can be mounted in its entirety on a manifolding attachment frame, its only operative connection with the typewriter frame being represented by the end H of fiexible element 69; it is, therefore, obvious that the transmission of movement from the typewriter carriage to the ribbon feed mechanism becomes a matter of extreme simplicity, which can be readily attained without removing the typewriter from its place of use.

It is obvious that although I have shown and described a mechanism for driving the ribbon feed mechanism, actuated by the carriage during its return movement, any other suitable driving arrangement may be used; the ribbon feed mechanism forming the subject of the present invention being entirely independent of the way in which power is supplied for driving its shaft 21.

Other constructional details of my invention may vary from those shown Without departing from the inventive idea, the drawings, therefore, should be understood as being intended for illustrative purposes only and not in alimiting sense. I accordingly reserve the right to carry my invention into practice in all those ways and manners which may enter, fairly, into the scope of the appended claims.

I claim:

1. In a typewriting machine, two ribbon reels, a ribbon adapted to be alternately wound upon one of said reels and unwound from the other, a driving shaft, a. reel engaging sleeve loosely mounted at each end of said shaft, clutch members shiftable on said shaft adapted to connect one or the other sleeve to said shaft, a shifting rod adapted to operate said shiftable clutch members, means directly actuated by said ribbon for operating said shifting rod, power storing spring means interposed between said operating means and said rod, for transmitting movement from the former to the latter, and frictional means opposing the movement of said shifting rod in either direction, said movement opposing means causing said spring means to store sufllcient energy, before transmitting to said rod the movement of said actuating means, to cause the movement of said rod to take place with a snap action.

2. In a typewriting machine, two ribbon reels, a ribbon adapted to be alternately wound upon one of said reels and unwound from the other, a driving shaft, clutch members shiftable on said shaft adapted to connect one or the other reel to said shaft, a shifting rod adapted to operate said shiftable clutch means, a bell crank lever in proximity of each reel, a spring interposed between one of the arms of each bell crank lever and said shifting rod, connecting the former to the latter, frictional means tending to oppose the movement of said shifting rod in either direction, a pull link member attached to the end of the other arm of each bell crank lever, said pull link member having a slot through which said ribbon is inserted, a member carried by said ribbon, blocking the further advance of said ribbon through said slot, when said ribbon is about to be entirely unwound from the corresponding reel, and causing said pull link member to follow the movement of said ribbon, and to actuate said bell crank lever, thereby causing its corresponding spring to restore power up to a. point when it can overcome the resistance of said movement opposing means, and shift said rod to reverse the ribbon feed with a snap action, and braking means tending to oppose the rotation of said reels.

3. In a typewriting machine, two ribbon reels, a ribbon adapted to be alternately wound upon one of said reels and unwound from the other, a driving shaft, a reel engaging sleeve loosely mounted at each end of said shaft, clutch members shiftable on said shaft adapted to connect one or the other sleeve to said shaft, a shifting rod adapted to operate said shiftable clutch members, means directly actuated by said ribbon for operating said shifting rod, power storing spring means interposed between said operating means and said rod, for transmitting movement from the former to the latter, a double conical friction shoe mounted on said shifting rod, and a spring member mounted in the path of said friction shoe, tending to oppose the movement of said shifting rod from either of its extreme positions to the other.

4. In a typewriting machine, two ribbon reels, a ribbon adapted to be alternately wound upon one of said reels and unwound from the other, a driving shaft, clutch members shiftable on said shaft adapted to connect one or the other reel to said shaft, a shifting rod adapted to operate said shiftable clutch members, a bell crank lever in proximity of each reel, a spring interposed between one of the arms of each bell crank lever and said shifting rod, connecting the former to the latter, a double conical friction shoe mounted on said shifting rod, a spring member mounted in the path of said friction shoe, tending to oppose the movement of said shifting rod from either of its extreme positions to the other, a pull link member attached to the end of the other arm of each bell crank lever, said pull link member having a slot through which said ribbon is inserted, a member carried by said ribbon, blocking the further advance of said ribbon through said slot, when said ribbon is about to be entirely unwound from the corresponding reel, and causing said pull link member to follow the movement of said ribbon, and to actuate said bell crank lever, thereby causing its corresponding spring to store power up to a point when it can overcome the resistance of said movement opposing means, and shift said rod to reverse the ribbon feed with a snap action, and braking means tending to oppose the rotation of said reels.

GUIDO M. SACERDOTE. 

